A | B |
Law of Original Horizontality | Rocks are deposited in horizontal layers |
Law of Superposition | Oldest rocks are on the bottom and youngest on top |
Law of Included Fragments | Oldest rocks are pieces inside other rocks |
Law of Cross Cutting Realtionships | Igneous intrusions that cut through sedimentary rocks are younger than rocks they cut through |
Unconformity | Gap in rock record |
Sill | Horizontal igneous intrusion |
Disconformity | Igneous rock deposited before next Sedimentary layer is layed down |
Absolute Dating | Being able to exactly date an event in geologic history |
Tree Rings | Method of absolute dating where each tree ring = 1 year |
Varves | Sediments in glacial lakes showing light and dark bands that = 1 year |
Half Life | Time it takes for radioactive element to decay |
5700 years | Half life of Carbon 14 |
RadioCarbon Dating | Way to date organic material |
Parent Material | Unstable radioactive element that decays into stable daughter material |
50 grams | Amount of parent material left after 1 half life if you had 100g to start with |